Disclaimer: Joanne Rowling owns these two.
Her eyes were impossibly black, Narcissa noticed. Just like her personality. Just like her hair, as dark as the night the same way hers was light. The light from the open window shone upon it and she grasped a few strands gently, gazed at it as the breeze blew it through the planes of her hand. The curtains billowed lazily by the windows. Were the windows open before? Narcissa felt the hair on the back of her neck stand up.
"Narcissa?" Her sister's sharp voice shook her back to reality. Bellatrix's wide eyes seemed to hold something else now. Narcissa abruptly let go of her sister's hair and took a step back, only to be grabbed by her shoulders by what seemed like claws. They would surely bruise later.
"Let me go, Bella," Narcissa murmured, hands weakly prying at her sister's.
"I'm not letting you go!" said Bellatrix, who continued, "Not until you tell me!" Narcissa stopped struggling, and resignedly looked her sister in the eyes. Bellatrix, seeing her sister was not going to fight anymore, relaxed and dropped her hands. "Why didn't you wait for me?" she demanded again, softly this time.
Narcissa considered. Bellatrix had supposedly perished after the war. To everyone, her sister, the mad and deranged with that she is, was dead. Everyone was so happy. Narcissa knew no different. At that time, the most important thing was keeping her family out of Azkaban. She had never gone back to search for her sister. It was one late evening, when she was getting ready to go to bed, that she showed up suddenly out of nowhere.
"Tell me, Cissy..." Bellatrix's voice said, urging.
"I thought you were dead," said Narcissa simply, "in fact, I was sure you had died!"
Her heart rate increased as Bellatrix suddenly exploded, "And that makes it okay to just go out seeing people again?! Didn't I mean anything to you, Narcissa?" Narcissa fingered her nightgown nervously and stared at the embroidery of her pillow.
She swallowed. "People need to move on, Bella. They need to move on or they won't be able to live life to its fullest. I want to live life to the fullest, Bella -"
"You lived with me, didn't you? We made each other live!" the dark witch exclaimed, her eyes narrowing. "Don't tell me all that was nothing! Don't tell you didn't have the time of your life with me! How could you just throw all that away?!" Bellatrix calmed down and took a shuddering breath before saying, "Didn't you love me?" She backed Narcissa into a wall. They were so close Narcissa could feel the breath of her sister hitting her face.
"Of course I did." Narcissa's mouth opened with the automatic response.
Bellatrix forced her chin up with her fingers and shoved a leg between hers. "Do you?" She asked again, pressing her body against her little sister. Narcissa reluctantly made eye contact.
"I... I do."
"Good." Bellatrix let go of Narcissa and wrestled the flimsy nightgown off of her. She dragged the younger witch to the neatly made bed and forced her onto it. "Where's your oh so lovely husband, Cissy?"
Narcissa pushed herself up by her elbows. "Lucius is...absent." She could not bring herself to answer that question. In truth, her husband was out drinking his days away, probably off stewing about the war somewhere in private. The last time she heard of him was that he had broken into a brothel and kidnapped several whores.
"Good," Bellatrix repeated, "good." She stood back and began to unlace her corset. Narcissa, lying prone on the bed, watched the black strings so intricately laced together come apart. Bellatrix dropped it to the floor and started to work on her dress. "I'm going to make you come so hard you'll wish you never thought I was dead." Narcissa shivered with want. She could see her sister's pupils dilate with desire. Bellatrix snapped off her garters and pounced on top of her, kissing her with fury.
Bellatrix thrust her tongue into her mouth and she moaned as the raven-haired witch cupped her bum. They separated and Bellatrix sucked at Narcissa's elegant neck, scratching with her teeth every so often. She kissed her way down her sister's chest, a hand grabbed roughly at a breast, tweaking the nipple. "Oh, Bella," Narcissa gasped. "I've missed you so..."
The older witch shoved her legs open. "Yes you did, and you just wouldn't admit it, would you?" Bellatrix growled. "Look how wet you are, slut!" She teased Narcissa's lips open and swirled her finger around her clit. She pressed hard on it, elliciting a cry from the blonde.
"Oh gods!" Narcissa yelled as her sister leaned down to nibble at her clit. Bellatrix teased at her opening with her tongue, always going past it but never quite reaching the place Narcissa wanted her to reach most.
"Tell me you want it, Narcissa!" Bellatrix stared at the other witch with fervid eyes. Narcissa thought she could sense desperation in them. "Tell me you want it and I'll give you it." She flicked at her clit.
Narcissa groaned. "Yes!"
She cried as the dark-haired witch drove two fingers inside her at once, filling her up again. Bellatrix pistoned in and out of her, a hand in her own cunt. Narcissa was close. She balled the covers in her fists. "Who do you belong to, Cissy?" Bellatrix's voice sounded strained and her cheeks were flushed with heat. She looked a truly magnificent creature. "Tell me who you belong to!"
Narcissa opened her mouth. She felt lightheaded. "I'm yours, Bella - yours!" she panted and threw her head back. Bellatrix continued her ministrations as she moved up to kiss her sister, her night-colored hair cascading around them both. The moonlight fell across two pale bodies as they writhed together on the enormous bed.
The tide brimmed over, and her walls contracted around Bellatrix's fingers. Narcissa's legs bucked with the intensity of her orgasm. She heard in the distance someone calling out her sister's name. Bellatrix howled her own orgasm, and collapsed onto the bed to face the younger witch.
Bellatrix licked her fingers. "You taste the same as you always did. Like summer days, Cissy."
Narcissa indolently brushed the hair away from her moist forehead. Bellatrix, in an unusual display of gentleness, held out her arms for her, and she exhaustedly rolled into the embrace, knowing how rare these moods were. The last thing she saw before falling asleep was the pitch blackness of her sister's hair, which appeared rather golden.